Antibacterial activity in Actinidia chinensis, Feijoa sellowiana and Aberia caffra

The antibacterial activity of extracts from various parts of plants (leaves, fruits and stems) was studied in Actinidia chinensis, Feijoa sellowiana and Aberia caffra. These are tropical plants used for food. The fruits (subdivided into skin, pulp and seeds), leaves and stems were separately extracted and tested, in triplicate, against eight Gram positive and Gram negative bacterial strains. All the extracts, except from the leaves of A. caffra, showed activity against all the strains employed. Inhibition of bacterial growth was tested against Na-cefotaxime, benzyl penicillin and tetracycline. The antibiotic activity of fruit resides essentially in the seeds. The antibacterial activity of extracts from vegetative plant parts was generally less active that from fruit extracts. The minimum inhibiting concentration (MIC) and minimum bactericidal concentration (MBC) were determined for all the extracts and showed exclusively bacteriostatic activity.